Vulcanizing apparatus



y 1944- E. A. LUXENB ERGER VULCANIZING APPARATUS Filed. Aug. 5, 1940 7Sheets-Sheet 1 1944- EA. LUXENBERGER 2,350,175 I VULCANI Z ING APPARATUS7 Sheets-Sheet 2 I Filed Aug. 3. 1940 7 y F J i 0 F 5Q a, 5 1 aw Z 9 Z;MW MIILY lfl/unlliliimw W W/9mm y 9 E. A. LUXENB-ERGER' 2,350,175

VULCANIZING APPARATUS I Filed Aug. 3, 1940 7 Sheets-Sheet 5 May 30,1944. E. A. LUXENBERG'ER 75 VULCANIZING APPARATUS Filed Aug. 3, 1940 '7Sheets-Sheet 4 wm w May 30, 1944. E. A. LUXENBERGER 03 VULCANIZINGAPPARATUS Filed Aug. :5, 1940 May 30, 1944. ENB 2,350,175

VULOANIZING APPARATUS Fileci Aug. 3, i940 TSheets-Sheet e mum;

resented May 30,1944

vummzmo Eugene Augustus Luxenberger, liiisha Ind,

or to Mishawaha Bother Woolen Application august a, lean, Serial No.350,738

(or. is-iv) My invention relates to the vulcanization of rubber articlesand has reference more particulariy to equipment whereby moldedarticles, such as cushions or mattresses of foamed or irothed latex, maybe produced expeditiously with assurance of uniformity and perfection.

In the manufacture of cushions, mattresses and the like of foamed orfrothed latex, large scale production has heretofore'been quite dimcultowing to the length of time required for vulcanization, the excessiveamount of floor space and equipment and handling of equipment that wasnecessary? and the careful supervision that was constantly required toavoid faulty production and excessive losses.

In general two types of equipment have been employed in making moldedarticles of rubber, one of which involved individual or gang molds,which, after filling with the compounded rubber, were introduced into anoven or vulcanizer by which the molds and their contents were subjectedto appropriate temperatures for the necessary length of time to curethe' rubber and the other of which involved individual or gang molds,each with its own heating facilities, such as a steam jacket,incorporated in the mold and by which each mold and its contents wereheated, neither of which types of equipment are emciently oreconomically adaptable to the making of molded tresses and the like.

These spongy rubber cushions of latex foam or the like are commonw madewith a large number of elongated openings extending upward nearly orentirely through the cushion or mattress and produced by a correspondinglarge numarticles of latex foam, suchas cushions, matber of cores in themold and the molds are not ally requires a difierent or new mold, themat-' 'te of mold costs is of paramountimportance and likely to beprohibitive unless the mold turnover is quite rapid or the number ofcushions produced per mold in a given time is quite large. Obviouslyalso the vulcanizing, handling, and

to rapidity of production and must also be suitable for or adaptable tothe various shapes and sizes of molds and changes in molds that may berequired from time to time. i e

Closely associated with the matter of mold costs is the amount orpercentage of losses through faulty processing as any percentage ofdefective and unusable products that occurs not only is a loss orwastage of the time and material involved in the manufacture thereof,but necessarily requires additional molds and equipment to provideallowance for such percentage of deiective or unusable production as islikely to occur.

Latex loam is a sensitive material, which must be handled carefully,especially immediately before, during and after gelling, at which timeor times movement thereof causes it to fall and lose The particularconditions under which curing is accomplished are especially importantas these cushions are quite large with relatively great thickness ordepth of material into which heat penetration is ordinarily quite slow,especially in the aerated form of the rubber, such cushions requiringapproximately two hours for vulcanization under usual vulcanizingconditions and of course necessitating an excessive number of molds evenfor small scale production. I have found, however, that by vulcanizingunder certain conditions with careful and exact control thereof,

vulcanization can be accomplished in greatly reduced time, even aslittle as twenty minutes, and

of course this reduction of curing time permits an approximately sixtimes greater mold turnover with an extraordinary saving in molds,equipment and floor space which relieves the manufacturer of suchcushions of its greatest obstacle to successful large scale production.Naturally, in either case, the length of vulcanization time varies withthe size of the cushions and the depth or thickness of material intowhich the heat must penetrate and also with the character of thecompound, but the relative saving of time prevails irrespective of thesefactors.

other facilities in connection with which the molds are used must besuch as will contribute Reverting now to the two types of equipmentheretofore in making molded rubber articles, the first above mentionedtype, namely the individual molds which after filling are introducedinto an oven or vulcanizer, is not suitable for nor satisfactorilyadaptable to the manufacture of latex foam cushions, not only because ofthe delay and loss of time necessarily occasioned in filling the batchof molds which the oven or vulcanizer accommodates and in transferringthem thereto before vulcanization of anyof the batch can. be proceededwith, but also on account of the difficulty in spreading the workeconomically unless there are sufilcient ovens or vulcanizers so that-the time of the mold filling and oven loading crew can be occupied byattending progressively to the mold filling and loading of a group ofovens or vulcanizers. some and unwieldy it is inconvenient and requiresconsiderable special equipment to handle same and load them in thevulcanizer. Moreover, with the variations in time that necessarily occurin filling the batches of molds and loading them in the vulcanizers itis difficult to maintain the exact conditions of temperature andhumidity that above mentioned which has been employed heretofore inmaking molded rubber articles, namely the individually heated molds, hasdefinite disadvantages by reason of which it is not suitable for moldingor vulcanizing latex foam articles. In the first place the provision offacilities for individually heating each mold adds greatly to the moldcosts and practically precludes any appreciable salvaging of moldexpense by remaking of.molds into changed forms or sizes which mayoftentimes be accomplished with the molds that are not individuallyheated. Furthermore, with the individually heated molds the necessaryatmospheric conditions for rapid and uniform penetration of heat intothe mass of latex foam and quick cure thereof, which as above pointedout is of paramount importance, are not obtainable and accordingly suchmolding and vulcanizing equipment, although it would eliminate thehandling and moving of the molds to fill and load them in the vulcanizerand other disadvantages of the above first mentioned type of molding andvulcanizing equipment is ent rely unsuitedfor latex foam molding andvulcan'zing.

According to my invention a vulcanizing chamber is employedin which oneor more molds are mounted, preferably removably, so that other anddifferent molds may be substituted at will, the mold chamber being ofsuitable size to accommodate the largest size molds that wouldordinarily Also as the molds are cumbertrolled times and when closed thevulcanizer, which is preferably insulated, affords a sealed enclosure towithstand substantial pressure and maintain in the vulcanizer anatmospheric condition as to pressure, temperature and humidity which ismost favorable to rapid. and uniform vulcanization.

Thus with my above mentioned equipment, molds of various sizes andshapes may be employed and the molds are filled in place in thevulcanizer so that no movement thereof occurs or is necessary after thefilling and closing of the mold. Immediately upon pouring, thevulcanizer,-which is self sealing, may be closed without any waiting ordelay and the gelling and vulcanizing proceeded with at once. Ventopenings are provided for evacuating the vulcanizer and also steaminlets which supply steam distributively at proper saturation andpressure and these openings or inlets are automatically operated underregulatable time control so that the articles in the molds not only areexposed in the vulcanizer to the exact conditions which I have found toeffect exceedingly and surprisingly rapid cure, but also for the precisetime to insure complete and perfect'cure.

Among the conditions above mentioned which appear to contribute to theunusually rapid cure are elimination of air which would interfere withrapid and uniform dissemination of heat and perhaps have somedetrimental drying eifectheating by direct application of wet steamwhich not only maintains the-molded article in moist condition but alsosupplies heat rapidly and unibe required and hence capable ofaccommodating molds of any smaller sizes. Thus the mold chamber isreadily adaptable by mere changeof molds to make cushions of a varietyof sizes and shapes.

The vulcanizer opens at each mold location. bein arranged so thatseparation occurs substantially at the parting place of the moldsections which are preferably arranged to part and separate withinterior of the vulcanizer affords convenient access at the same time tothe interior of the mold.

'-the opening-of the mold so that access to the formly-and avoidance ofevaporation which consumes heat that otherwise would contributematerially to vulcanization. Also special molds are employed with thinwalls of high heat conductivity'so that heat transmission therethroughis facilitated.

I In addition, cooling facilities 'are provided and arranged to insureprompt cooling of the molds,

up to commencement of vulcanization. Special lifting movement of theupper mold sections is also provided not only to avoid injury to themolded article in opening the mold but also to afford ample clearancefor pouring, and the opening of the vulcanizer and mold is eifected insuccessive stages to permit release of any adherence of the moldedarticle to the mold sections which might cause tearing if the mold wereopened without this precaution.-

The object of my invention is. in general. to expedite and facilitatethe production of molded articles of latex foam or the like withassurance of uniformity and perfection thereof. Other objects are toeffect sufilcient increase in the output from given equipment so thatthe equipment requirements are reasonably proportionate to the output:to avoid variations in production which may affect the serviceabilityand acceptability of the product; to avoid any movement or disturbanceof the article from the time of pouring thereof until it is in a safecondition for handling; to provide equipment which is readily andeconomically adaptable to the making of articles of various shapes andsizes; and to permit continuity of production and positive control ofthe various conditions affecting the perfectness of the product so thatthe articles are produced rapidly without delays or loss of time andwithp out necessitating the constant and exact supervision that has beenrequired heretoiore-=.-these accompanying drawings in which:

Fig. 1 is a top or plan view of a vulcaniz'er constructed in accordancewith my invention, this view showing the vulcanizer when closed;

Fig. 2 is an end view thereof of the closed vulcanizer; I a

Fig. 3 is a similar end view, but showing the vulcanizer in the openposition;

Fig. 4 is a sectional view taken substantially on the line d-d of Fig.l, but showing the vulcanizer in the open position of Fig. 3;

Fig. 5 is a longitudinal vertical sectional view through one end portionof the vulcanizer, taken substantially on the line 5-5 01 Fig. 2;

Fig. 6 is a front view of one end portion of the vulcanizer with partsbroken away and the operating mechanism at the end shown in sectionsubstantially on the line 6-6 of Fig. 2:

Fig. 7 is an enlarged detail view on the line 1-1 of Fig. 6 showing oneof the vulcanizer closins springs:

Fig. 8 is a top view showing end portions of two adjoining vulcanizerswith cooling equipment for cooperation with each of the two vulcanizers:

Fig. 9 is a front view of the structure shown in Fig. 8 with thevulcanizers in the open position to permit cooling of the molds therein:

Fig. 10 is an end view of an open vulcanizer showing the arrangement ofthe cooling mechanism at the remote end thereof Fig. 11 is a fragmentarydetail perspective view of an outlet from the cooling device: and

Fig. 12 is a diagrammatic view illustrative of controls by whichoperation of the press is accomplished.

For illustrative purposes a preferred embodiment of the invention isshown comprising a double deck vulcanizer wherein there are twosuoerposed mold levels at each of which one or more molds isaccommodated. dependin upon the size thereof. the molds being arrangedto open and close with the opening and closing movements of thevulcanizer. and each mold being conveniently accessible for filling andremoval of the molded article when the vulcanizer is open.

This double deck vulcanizer comprises a bottom section 28 with bottomwall 2|. a middle section 22 which is o en at the top and bottom. and acover section 23 with top wall 2|, which said sections close together insuperposed relation to form a closed chamber and are separable from oneanother so as to aflord access between the top and middle sections andbetween the middle and bottom sections, appropriate mechanism beingprovided which is operable to separate and close together the sectionsas here required.

The bottom section 28 is built into the base 25 of the vulcanizer andthis combined base and bottom section is secured directl 'to the flooror other foundation and carries the mechanism by which the vulcan zersections are opened and closed. This mechanism comprises duplicatemechanisms at the opposite ends 01' the vulcanizer operatingcorrespondingly in unison from a main shaft 26.01 two part constructionas here-' inafter pointed out, which extends lengthwise of thevulcanizer at the rear of the bottom section and is journaled inbearings 21 rigidlv secured to the vulcanizer base 25, at the oppositeends respectively thereof. Each end of the shaft 28 is provided,immediately beyond the respective bearing 21, with a correspondinglypositioned crank 28 for operating the duplicate mechanism at that end orthe vulcanizer, the so-called duplicate mechanism at each end beingcontained in a housing which is a rigid part of the combined base andvulcanizer section 20 and has an inner portion 29 and an outer guardplate portion 20 which support parts or the vulcanizer opening andclosing mechanism at the respective end of the vulcanizer.

Each said duplicate mechanism has an arm 8i with trunnions'32 at one endengaged in bearings 33 of the housing portions 29 and and each arm 3|has a lateral extension at this trunnioned end pivotally connected at 34to the end of a link 35, the other end of which engages the pivot pin 36of the respective crank 28 by which the arm 3| swings in its pivotalmounting 33. The end of the arm 3| remote from the pivotal mounting 33is pivoted at 31 to the end of a short link 38, the other end of whichis pivoted at 39 to the respective end of the top or cover section 23 ofthe vulcanizer, the arrangement being such that when the two cranks 28are in the upward dead center position with respect to their links 35 asshown in Fig. 3, the cover section 23 of the .vulcanizer. islifted'thereby from the middle section 22 as shown in said figurewhereas when the cranks 28 are in the opposite dead center position withrespect to their links 35 as shown in Fig. 2 the cover section 23 isclosed down tightly against the surrounding top margin 48 of the middlesection 22 as shown-in said Fig. 2.

Another arm 6| has trunnions 42 at or'ie end engaged in bearings $3 ofthe housing portions 29 and 30 and the opposit end of this arm H ispivotally connected at M to one end of a link which has the other endpivoted at 56 to the respective end of the middle section 22 and thisarm 4| has a lateral extension t1 the outer end of which is pivoted at68 to one end of a link 39. the opposite end of which is pivoted at 50to the outer side of the respective arm 3| between th pivots 32 and 3'!thereof so'that swinging of the arm 3| imparts through the link 49 asomewhat similar swinging movement to the middle section 22 from thelower section 28 to a position approximately half way between the raisedcover 23 and the bottom section 20 as shown in Fig. 3. Movement of thearms 3| to close the cover section 23 against the middle section 22 inlike manner imparts movement to the arms 4| to simultaneously close themiddle section 22 down tightly a ainst the surrounding top margin 5| ofthe bottom section 20 a, shown in Fig. 2.

To impose a tension on the cover section 22 to hold it tightly closedagainst the middle section 22 and to impose a like tension on the middlesection 22 to hold it tightly closed against the bottom section 22, theouter trlmnion 32 of each arm 3| and the outer trunnion d2 of eachsufllcient tension to hold the sections 23, 22 and 2i tightly closedtogether in the closed position of the vulcanizer.-

Furthermore each section 23 and 22 has around its inner margin a sealingstrip channel it containing a sealing strip 56 of resilient material,such as rubber, which projects sufllciently from said channel 33 so asto tightly compress against therespective top margin 43 or SI of theopposed under section 22 or 23 and seal the joint so that substantialpressure may be employed and maintained within the interior of thevulcanizer. All of the walls of the vulcanizer are also insulated sothat desired temperatures for vulcanization may also be maintained inthe closed vulcanizer.

Since the pivotal axis of the trunnions 42 is well in advance of thepivotal axis of the trun-. nions 32 the opening movements of the coversection 23 and the middle section 22 is such that the middle section 22when raised swings a substantial distance rearwardly from the front ofthe bottom section 2ll,as shown in Figs. 3 and 4, so that overheadaccess is provided to the in- 2,sso, r75

- are pivoted to their respective sections 22 and terior of the lowervulcanizer section 20 which e is desirable to facilitate pouring intothe mold pan with which the bottom section is provided, and at the sametime the cover section 23 when raised swings a somewhat similar distancerearward from the front of the middle section 22 to permit similaraccess to a mold pan in the middle section 22.

.For reasons hereinafter more fully explained it is desirable that inthe opening movements of the sections 23 and 22 each of these sectionsshould be lifted perpendicularly from the section immediately below in asubstantial portion of its initial opening movement and it is for thepurpose. of permitting thi initial perpendicular or straight linemovement that the arms 3| and 35 are connected to their respectivevulcanizer sections 23 and 22 by the links 33 and 45.

To impart this initial perpendicular movement to the sections 23 and 22the top and bottom sections 23 and 20 are provided at each end. withguides which cooperate with rollers on the ends of the middle section22, the guides of the lower sectiqn 20 which are indicated at 51 beingrigidly secured to the combined base 25 and bottom section 23 and eachhaving a plate like portion 83 extending upwardly in outwardly spacedrelation from the respective end of the section 23 as shown in Fig. 5and provided with a vertical notch 53 to accommodate a roller 33 on thelower pivot I of the link It, said roller 33 being interposed betweenthe leaves the notch 33, the length of the curved guiding edge 33 beingsuch that in the fully raised position of the middle section 22 theroller 33 does not leave the cam 32.

Thus as the arms I swing the middle sec-:

tion 22 to the raised position the engagement of the rollers 80 with thenotches I9 imparts a perpendicularmovement to the section throughout thelength of the slots 33, the links it swin ingjt the time on their pivots4| to allow such the rollers it ride rearwandly and upwardly alongthe'cam edges 33 permitting the section 3 23 substantially midwaybetween the front and rear thereof so that these sections are suspendedfrom the links in substantially a balanced manner, and of course asthese sections are free to swing on their respective pivots 46 and 33,precautions are desirable to avoidundesirable pivotal' movement. This isaccomplished in the case of the middle section 22 by a parallel link andlever arrangement at each end of the section comprising companion linksI! and levers II paralleling the links 43 and arms or levers IIrespectively, the lever ll being pivoted at I to the housing portion 23and the link 45 being pivoted at its upper: end to the outer end of thelever or arm ll as at I, and at its lower end to the end of the section22 as at St. Each arm ll has an extension BIbeyond its pivot 42 and eachlever or arm II} has a corresponding extension 31* beyond its pivot Mthe outer ends of which said extensions 31 and G1 are connected by alink 33 to cause the lever II to swing in unison with the arm 6!.

By reason of this parallel link and lever arrangement, swinging of thesection 22 on its supporting links 45 is controlled and the presentarrangement is such that the section is maintained horizontal andparallel to the section 23 in all positions of its opening and closingmovement. It will be noted that in the closed position of the vulcanizerthe link 45 swings down to a position against the upper end of the camextension 62 which has an upright terminal face 62'- against which thelink It moves laterally when the section 22 is closed down against thesection 29.

The upper or cover section 23 also has a guide serving to hold the guide39 in upright position and the section 23 parallel with the section 22so long as both rollers are engaged in the slot II. The rear arm I3 ofeach guide 89 is shorter 7 than the front arm 14 thereof and is removedfrom engagement with both rollers II and I2 after the upper section 23has been lifted a substantial distance from the middle section 22whereas the front arm I3 is of suflicient length to remain engaged withthe upper roller II at all times. By reason of this differential lengthof the arms I3 and I4 a direct upward straight line lift is imparted tothe section 23 during the initial portion of its opening movement afterperpendicular or straight line movement, and

when the top of the notches 89 are reached.

which the freeing of th arm I3 from the lower roller I2 permits thesection 23 to beglna rearward tilting which continues after the arm I3is withdrawn from engagement with the upper roller II and is caused'bythe continuing en;- gagement of the arm It with the upper roller It andthe rearward pull of the arms 3| on the section 23. The lower end of thearm 13 is curved as at I! to facilitate entrance of the rollers II and12 in the notch 13 and this curved formation also serves tocontrol thetilting of the section'23 and cause a gradual shifting of the sec- .tion23 to and from its position of parallelism with the section 22 in theclosing and opening movements respectively of the section 23.

Thus in the opening of the vulcanizer each section 23 and 22 issimultaneously lifted, the

rate of lift of the section 23 being substantially twice that of thesection 22 so that as the section 22 is lifted from the section thesection 23 is being lifted substantially an equal distance being steppedrearwardly and tilted with respect r to the section 22 so that overheadaccess is afforded to the forward portions of both sections 22 and 263.

For operating the shaft 26 to impart the opening and closing movementsto the sections 23 and 22 any convenient source of power may beemployed, preferably an electric motor 16 connected through a suitablereduction gearing ll with the shaft to operate the latter at arelatively low speed. This motor and reduction gearing may be combinedin a unit which is secured as at 18 to the rear of the vulcanizer base25 and has a double ended output shaft 19 in line with the two sectionsof the shaft 26, which of the shaft 26 being coupled at its inner end tothe corresponding end of the shaft 19.

A braking device is provided which acts upon discontinuance of operationof the motor 16 to impose a braking action on the output shaft 59 shapesmay be readily installed to optionally make cushions of any desiredsizes or shapes within the dimensions of the vulcanizer, the pans Bil ofthe two molds being located respectively near the top of the middlesection 22 and near th top of the lower section 20'and the top sectionsM of the molds being located respectively at the bottom of the coversection 23 and at the bottom of the middle section 22 so that the topsections 8! of the molds move respectively with the cover section 23 andthe middle section 22 to and from its mating mold section 80 in theopening and closing movement of the vulcanizer.

For mounting the mold pans 88, any suitable mounting facilitiespermitting removability and adjustability of the pans may be employed,each section '22 and 26 being provided in the illustrated embodimentwith a'rail 682 at each end which is secured to the inner side of therespective end wall and provided with a dovetailed groove 82 along theinner face thereof to accommodate brackets, bolts or other suitable fas=tenings or fittings that may be required to mount the particular moldpans, it being understood of course that such brackets or fittings areadjustable along the groove 83 and may be secured in adjusted positionsto position the mold pan in the desired location.

as aforesaid is preferably divided, each section to stop operation ofthe latter promptly and avoid overrunning, the braking device not beingshown or explained in detail as such braking devices are well known, andthe motor 16 is controlled to permit accurate stopping thereof uponcompletion of the closing movement of the vulcanizer and upon completionof the opening movement thereof as well.

This vuicanizer is ofsuitable size or horizontal dimensions toaccommodate therein molds of the largest size contemplated, as forexample moldsv for making automobile cushions oi the usual lengths andwidths, two of such molds being shown in place in the illustratedembodiment. Such cushions as above indicated are vusually formed with alarge number of elongated openings extending upwardly in the cushionbody nearly to the top thereof and in making suchcushions a lower moldsection or pan to of cushion shape is usually employed into which thefoamed latex is poured and this mold has a cover section 8! which closesdown against thesurrounding margin of the pan to and is provided withdepending hollow cores 22 arranged to extend an appropriate distanceinto the pan '0 to form the required openings in the cushion. The twomolds employed in the present In the present embodiment an angle iron 86is secured to-each rail i82 with a flange 85 extending inwardly and thepan dd, which is long enough to be mounted directly on these angle irons85, has an outturned marginal flange 86 therearound, the portions ofwhich at the opposite ends of thepan 85 rest on and are secured to theangle iron flanges 85 as will be readily understood. Rails of angle ironor other form may extend lengthwise of the vulcanizer chamber betweenthe opposed grooved rails H82 and have end formations or fittings bywhich they are adjustably secured at their ends in the dovetail grooves83 so that one longitudinal rail may be located near the front of thevulcanizer chamher and the other near the rear in selected spacedrelation from one another and these longitudinal-'- ly extending spacedrails may have a number of small mold pans, such as those for individualseat or chair cushions, mounted thereon in adjoining relation lengthwiseof the vulcanizer.

Thus it will be understood that the grooved rails I82 or other similarsupporting means that may be provided for the mold pans afford in eilectuniversal and adjustable mounting facilities by reason of which moldpans of various shapes and sizes may be readily mounted in any selectedor appr priate position in the top of the iection 22 and likewise in thetop of the section Similar rails 01- with dovetailed grooves a:

along the inner sides-are provided at the opposite ends of the sections23 and 22 at the bottom thereof to support the top or core sections llof the molds, these rails 81' however not being fixed in place but eachpivoted at its rear end to the respective sections 23 and 22 asindicated in parallel relation to the bottom plane of thei section 23 or22 or may be released to swing downwardly therefrom.

These rails 21 likewise permit mounting there-" on oithe top sections ofmolds or various sizes and shapes and they also permit adjustableproperly mounted on the rails l1 and the latter latched in the normalupraised position the. mold section 8| that is moimted at the bottom ofthe vulcanizer section 22 registers with the mold pan 80 in thetop ofthe lower section 20 when the two sections 22 and 20 are closed togetherand that the mold section ll is lifted out of and away from its matingpan as when the section 22 is lifted from the section 2!. Likewise thetop section 8| of the upper mold moves to and from its mating pan 8|upon movement of the top section 23 to and from the middle section 22.

Assuming that the vulcanizer is open as shown in Figs. 3 and 4 with themold pans II in place and the mold sections ll latched up inposition atthe bottom of the respective sections 22 and 22, a measured quantity oflatex foam is poured in each pan ll sufilcient so that when the-uppercore sections II are closed against the pans .0 with the cores .2projecting ,downwardly into the pans 80 and into the latex foam therein,the latex foam will completely fill the mold space and assume thereinthe shape that is to be imparted to the finished cushion.

The motor ll is then operated torotate the shaft-26 a half turn wherebythe vulcanizer closed with the top section 23 sealingly engage againstthe surrounding top margin of the middle section 22 and the lattersection sealingly engaged with the surrounding top margin of the bottomsection 2| so that a closed pressure chamber is provided containing themolds "-8! which are then closed. The latex foam in the molds is thenvulcanized while the vulcanizer is closed and after vulcanizationthereof the shaft 28 is again rotated a farther half turn and therebyopens the vulcanizer and at the same time opens the molds whereupon thevulcanized cushions are removed from the molds and the molds refilled.

Because of the cores l2 projecting downwardly into the vulcanized massof latex foam in the pans 80 it is important to separate each top moldsection 8| from its mating pan I! in the direction of the longitudinalaxes of the cores '2 so as to avoid tearing or mutilation of the moldedcushion body and it is for this reason that the opening and closingmechanism for the vulcanizer is arranged, as hereinbefore explained, toimpart an initial perpendicular movement to each section 23 and 22 asthe vulcanizer opens, this initial perpendicular movement being ofsufficient extent to lift the cores entirely from the vulcanized body oflatex foam in the respective mold pan it before any lateral or tiltingmovement of the core section 8| occurs.

For vulcanizing-the latex foam in the molds ill-8| wet steam is employedand the vulcanizing chamber filled therewith at a definite pressure.approximately three pounds, to afford the required temperature,approximately 220 F. to vulcanize the latex foam, the wet steam beingemployed not only because it is an especially effective heating mediumbut also to preserve the latex foam in a moist condition in which heatpenetration is especially rapid. Moreover it is important to maintainthe prescribed pressure so as to avoid any evaporation of water that maybe present in the chamber or latex compound as operation of substantialamounts of heat which otherwise would expedite the cure but also lessensthe heat conductivity of the latex foam. Also, the molds "-1! are ofspecial construction as above pointed out, being made with thin walls ofhigh heat conductivity in accordance with the disclosure in applicationSerial No. 319,234, filed February 16, 1940, by myself and Herbert G.Erich and Marion M. Cunningham so that heat transmission therethrough israpid and it is to be understood that these molds are not sealed but thetop section 2| has a somewhat loose closing relation with the pan IIIand moreover the top section is provided throughout its area withnumerous small vent openings.

Steam is furnished to the vulcanizer from any suitable wet steam sourcethrough a pressure regulator and a valve :2 (see Fig. 12) to a pair ofinlets 82 which are connected to the opposite .ends respectively of apipe loop 9|, the middle length 95 of which is located along the frontwall of the vulcanizer near the bottom and has numerous upwardly facingopenings at at intervals therealoaig through which the steam isdischarged into the vulcanizer chamber distributively throughout thelength thereof.

The steam pressure regulator is not shown or described as such pressureregulators are well known and are adjustable to supply steam at anyselected pressure and it will be imderstood that by setting the pressureregulator at a certain selected pressure the pressure of steam suppliedto the vulcanizer is thereby controlled so as to maintain a pressure ofsteam in the vulcanizer atthe selected pressure. Thus if the pressureregulator is set at three poimds the steam in the vulcanizer will bemaintained at the.

three pounds pressure.

It is important, as above pointed out, to evacuate the air from thevulcanizer so that the vulcanizing chamber is completely filled with thewet steam and moreover it is important to relieve the steam pressure inthe vulcanizer before the latter is opened to remove the'vulcanizedcushions from the molds For this purpose a vent pipe 91 is providedalong the rear of the vulcanizer chamber near the bottom thereof with apair of outlets 98 leading therefrom and this pipe 81 has numerousopenings 98 at intervals throughout its length and leading into thetopthereof. The outlets lead through a valve I (see Fig. 12) by which thesevent facilities may be opened or closed as desired.

Moreover a drainage outlet MI is provided with a screen I02 thereoverand leading from the bottom of the section 20 as indicated at I" toremove condensation which may accumulate in the vulcanizer and thisdrainage outlet is controlled by a check valve ill (see Fig. 12) whichis arranged to operate so as to permit water drainage when thevulcanizer is open but closes when the press is closed and steam isintroduced therein.

The latex foam must be permitted or caused to gel before vulcanizationis proceeded with and is compounded to set or gel in a minimum of suchevaporation not only robs the vulcanizing 7s a temperature between 90and 100 it, th

molds being preferably artificially cooled when the vulcanizer is openedso that the proper pouring temperature thereof is attained during thetime required to strip the vulcanized cushions from the molds and cleanthemolds for the next molding operation.

. The vulcanizer itself in its walls and elsewhere retains residue heatfrom the previous vulcanizing operation which is imparted to the moldand its contents when the vulcanizer is closed, and the latex iscompounded so that this residue heat in addition to that remaining inthe molds causes the latex to gel promptly upon closing the vulcanizerwithin a period of five minutes thereafter during which the introductionof steam is delayed.

In the making of cushions or other articles of latex foam with thisequipment a certain cycle of operations takes place. First, startingwith the vulcanizer open as shown in Figs. 3 and s and both molds openas shown in Fig. 3 and cooled to the required pouring temperature, theproper amount of latex foam is poured into the pan SE) of each mold.Then the shaft 26 is operated to close the vulcanizer as shown in Fig. 2and with the closing of the vulcanizer each of the mold core sections 8iis simultaneously closed down in proper molding position relative to itsmating mold pan 88 so that the cores 82 project downwardly into the moldpan and into the latex foam therein and the latter then completely fillsthe mold and is ready for gelling and vulcanizing.

After the vulcanizer has beenthus closed the vulcanization is notimmediately proceeded with but the latex foam in the molds is firstallowed to set or gel in the mold form, such setting or gelling beingcaused to occur on account of the nature of the compound and therelativeily mild heating thereof whichoccurs upon closing the vulcanizerdue to residue heat accumulated in the walls of the vulcanizer andelsewhere in the previous vulcanizing operation. A period of fiveminutes is ample allowance to insure setting or gelling.

At the conclusion of the five minute gelling period the vent valve I isopened and the steam inlet valve 92 also opened so that the incomingsteam forces the air out of the vulcanizer chamber and the vent valve i8is allowed to remain open until all of the air is exhausted and completely replaced with steam. Thereupon the vent valve I09 is closed andthe steam supply valve 92 remains open until completion of the cure.

The time of closing the vent valve lull may be determined by thermometerreading or the valve -may be actuated automatically by thermostatcontrol inasmuch as an appropriate time for closing the vent is when thetemperature in the vulcanizer reaches 212 F. Since, however, with otherconditions constant, such as the pressure and rate of steam supply, thesize of the vulcanizer chamber and the rate of exhaust or venting, asthey are in the present case, the time required to evacuate the air andfill the chamber with steam is. uniform, the closing of the vent valveI" may be governed or controlled by lapse vulcanizer for the length oftime required to properly vulcanize or cure the latex foam in the molds.Due to the temperature of approximately 220" P. which is maintained inthe vulcanizer hy the steam pressure, the wet condition of the steam,the absence of any air, the rapid trans mission of heat through thespecial mold, the cure is effected in the remarkably short time ofapproximately twenty minutes, so that the total time from the closing ofthe vulcanizer to the completion of the cure is approximatelytwentyeight minutes.

. It will be understood, of course, that the drainage check valve ltd(see Fig. 3.2) is closed during the vulcanizing period above mentionedand only opens or is opened at such time as there is no pressure in thevulcanizer chamber so as to permit drainage of any water that maycollect in the bottom of the section it.

At the end of the curing period of twenty minutes the steam valve s2 isclosed and the vent valve ltd immediately opened to relieve the pressurein the vulcanizer and restore therein atmospheric pressure at which thevulcanizer may safely be opened, which relief of pressure occurs quitequickly, whereupon the shaft lid is advanced a half turn thereby openingthe vulcanizer and at the same time opening both molds Because of themoist condition maintained in the vulcanizer during vulcanization andthe moist condition of the latex foam thus insured. the

- mold sections usually separate quite readily from the vulcanizedarticle. As aprecautionary measme, however, to avoid tearing or damageto the and the steam pressure. is maintained in the 1| cushions whichmight occur on account of adherence or sticking of the molded cushion atsome places in the mold sections, the vulcaniaer is preferably arrangedto first open only part way or sufliciently so that the operator mayreach in and free the cushion from the mold sections, after which theopening movement is resumed and the vulcanizer fully opened. Thereuponthe molded cushions are removed and the vulcaniaer and molds preparedfor the next pouring.

In the molding of these articles, more or less of the latex foam usuallyextrudes from the mold cavity between the mold pan and core section andalso through the vent holes heretofore re ferred to as provided in thecore section 8i, and when the vulcanized cushions are removed from themolds, extruded portions remain on or at mold sections 8| may becleaned, after which the sections 8| are swung'up and latched in place.

Obviously in cleaning the molds, scraps of the extruded vulcanized latexfoam may fall down into the bottom section 20 of the vulcanizer andmight collect around the strainer I02 and interfere with drainage.Accordingly it is preferred to provide in the bottoinsectionjl below themoldsepctiou ill a perforatedpanlli, removably valve I the e i n al o sI; o hawrmn ms walls of said; section collect? any scraps thatmayvfalldown intothe. bottom section 2|, and this rf d p nt w h i abov hsteam inlet i e filiser eaalso toi stribu ivelyzaspread the suppliedsteam to the vulcanizer space thereabove. Incidentally it is alsoimportant before closing the vulcanizer to carefully clean the topmargins III and 3| of the vulcanizer sections 22 and 20 to make surethat there are no scraps or other particles thereon which wouldinterfere with sealing thereagainst of the sealing strips 33 of thesections 23 and 22 respectively.

For cooling molds 3II-3I after the vulcanizer is opened, and also tosome extent to cool the atmosphere in which the operator is necessarilyrequired to work in attending to the molds, cooling facilities areprovided at each end of the vulcanizer. Such cooling facilities comprisea. duct IIII leading from some source of supply of cooled air underpressure and preferably refrigerated, said duct terminating in outletsI33 and I33 catedat proper elevations and with proper directionalfacilities to blow cooled air against the mold sections 33 and ti ofboth molds when the vulcanizer is open. Accordingly there is a cooledair outlet I33 from the duct I31 arranged as shown in Fig. 9 at anelevation to discharge into the opening between the raised sections 23and 22 and another outlet I03 arranged at an elevation to discharge intothe'opening between the sections '22 and 20, there being a set of suchoutlets I33 and III! at each end of the vulcanizer near the frontthereof. Each outlet I03 is divided and provided with upper and lowerbailies or vanes III! and III respectively-as shown in Figs. 9 and III,the upper baflles II3 being arranged obliquely and turned rearwardslightly so as to direct substantially half the cooled air from theoutlet I33 distributively against the nearest half of the underside ofthe upraised mold section 3| of the upper mold and the other bailies IIIbeing downwardly inclined so as to direct-the other half of the cooledair from the outlet I33 distributively against the top of andinto thenearest half of the mold pan 33 of the upper mold. I

mentalitiesto cause the operations to occur at selected times and tocontinue .for selected periods of time as may be required.

In the time control which is shown diagrammatically in Fig. 12 a timershaft III which carries a series of control disks III, III, I23 and I2Iis rotated slowly by a variable speed motor I22, a suitable speedcontroller I23 being provided by which the speed of the motor I22 may bevaried as required for increasing or decreasing the speed of operationof the shaft III to vary the length of time for the cycle of operationsthat I A three wirefeed, the conductors of which are indicated at I23,I23 and I23, supplies current to the three phase motor 13 through athree leaf switch I21 the three leaves of which are operable conjointlyin unison by the disk I2I to make connections of the conductorsl23, I23and I23 The lower outlet I3! is set somewhat forwardly of the upperoutlet I33 as shown in Fig. 10'and is divided as shown in Fig. 8 into arear outlet portion H2 and a front outlet portion II 3, the rear outletportion II2 being arranged to direct the cooled air therefrom somewhatupwardly against the underside of the nearest half of the upraisedsection 3I of the lower mold while the front outlet portion I I3 hasbames I warranted to direct the cooled air therefrom against the top ofand into the nearest half of the mold pan 33 of the lower mold. DampersH3 and H3 are pro-.- vided in the outlets I33 and Ill respectively,simultaneously operable by a connecting rod 3' which has a handle I I3for manual manipulation so that the operator can control the supply 01cooling air at will. 1

provided arranged in spaced end to end relation; and between adjoiningvulcanizers, a single duct is preferably provided with a pair of outletsI33 and III! atone side to service the vulcanizer at that side and apair of similar outlets I33 and I33 at the opposite side toservice thevulcanirer s5 at the latter side as will be readily understood from theillustration thereof in Figs. 8 and 9.

Control of the various operations of the vu1-.

.canizer may be accomplished manually if desired,

with conductors I23, I23 and I33 respectively,

which lead directly to th motor 13. A cam follower I3I is provided whichcooperates with the periphery of the desk Hi to control the openini! andclosing of the switch I21 and this disk has a notch I32 in which the camfollower I3I is located when the vulcanizer is in its open position, atwhich time the switch I21 is open and no current is supplied to themotor 13 and the latter after described, the conductor I33 leading tothe controller I23 which is connected to the motor I22 and the otherconductor I33 leading through a switch I33 to the motor I22. The switchI33 is controlled by a cam follower I33 which operates with theperiphery of the disk in and the latter has a notch I31 arranged withrespect to the notch in of the disk In so that the In practice,batteries of these 'vulcanizers are follower I33 is in its notch I31 atthe same tiihe that the cam follower I3I is in the notch I32 and whenthe cam follower I33 is in the notch I31 the switch I33 is open and nocurrent is supplied therethrough to the-motor I22.

However a Jumper I33 controlled by a push button switch I33 is providedto by-pass the.

switch I33 and provide a connection of the conductor I33 ,to the motorI22 so long as the push button switch I33 is held in the closedposition. Thus the motor I22 can be operated while the switch I33 isopen and of course when the motor I22 is operated the shaft H1 and allthe disks II3, II3, I23 and I2I'arerotated.

The disk H3 is of such shape that in allpositions of'rotation thereofthe switch I33 remains closed'except when the cam follower I33 isopposite the notch I31 or opposite another similar notch I49 which islocated near to the notch I31 and is reached whenthe disk has madealmost a complete revolution from the position in which the notch I31 isengaged by the cam follower I39. Thus when the shaft III and disksII8-I2I are p in the idle position shown in Fig. 12 with the camfollower I36 engaged in the notch I31, the motor I22 may be started bytemporarily pressing the push button switch I39, whereupon the disk II8starts turning thereby moving the notch I31 away from its cam followerI36 and closing the switch I35 which remains closed and continues theopen atlon of the motor I22 until the disk I I8 has made almost acomplete revolution and the. cam follower I38 seats in the notch I40,whereupon the switch I35 opens and the motor I22 becomes idle until thepush button I39 is again pressed. when the push button is then pressedagain the motor I22 again starts and the cam follower I36 is lifted outof the notch I40 and engages the intervening rise I which holds theswitch I35 closed and continues the operation of the motor I22 for therelatively short interval until the notch I31 arrives at the location ofthe cam follower I38 which then retracts into the notch I31 and opensthe switch I35, and of course the motor I22 then stops.

The disk II9 controls the vent valve I which is operated by a solenoidI42 which when enerenergized.

Current is supplied to the vent valve solenoid I42 from the conductorI34 through a branch conductor I44 and from the conductor I33 through abranch conductor I45, switch I46 and conductor I41 and the switch I46 iscontrolled by the disk I I 9 through a cam follower I48 which cooperateswith the periphery thereof.

raised section I56 being of sufllcient circumferential length to retainthe switch I21 closed and continue the operation of the motor 16 onlyuntil the vulcanizer is closed at which time the raised section I58passes beyond the cam follower I3I and the latter retracts into the lowcircumferential portion I51 or the disk I2I thereby opening the switchI21 and causing the motor 16 to stop with the vulcanizer closed.

The low circumferential portion I51 extends around the disk |2I nearlyto-the notch I32, a

divided rise I58 being provided just aheadof the notch I32 which saidrise I58 at the proper time,

engages the cam follower I3I to close the switch I21 and operate themotor 15 to open the vulcanizer.

As before indicated it is desirable to only partially open thevulcanizer asa precaution so that the operator may release any adherenceof the molded article to the mold sections before the vulcanizer isfully opened and for this reason the rise I58 is divided by a notch I59which comes I59 of the disk I2I are arranged to come opposite theirrespective cam followers I36 and I3I at the same time so that when thenotch I59 opens the switch I21 and stops the motor 15 the notch M0likewise opens the switch I and StOPs the timer motor I22 therebystopping the rotation of the shaft H1 and disks II8--I2I.. Accordinglyto complete the opening movement of the vulcanizer it is necessary forthe operator to temporarily press the starter button I39 which startsthe motor I22 and engages the front portion of the rise I58 of the diskI2Iwith the cam follower I3Iand closes the switch 3 I21 until the notch532 is reached whereupon the switch I21 opens and the vulcanizer remainsin the fully opened position.

In the normal inoperative position of the shaft I III and disks II8I2Ias shown in Fig. 12, at which time the vulcanizer is open, the camfollower I4l is opposite a low section I49 of the periphery of the diskI I9 and the switch I48 is open and no current is supplied to thesolenoid I42 and the vent valve I90 accordingly is open;

Current is supplied to the steam valve solenoid I43. from the conductorI 34 through a branch which time the vulcanizer is open, the camfollower Il4-is opposite a low section I55 of the peripheryof the diskI28 and the switch I52 is 4 open and no current is supplied to thesolenoid into operation immediately. after the shaft 1.

and disk II8I2I start to rotate from the Fig. 12 position, and this riseI 56 deflectsthe cam follower I3I to close the switch I21 and cause theThus it will be understood that the time the vul-- canizer is partiallyopened is entirely under the control of the operator who accordingly canhave whatever time may be necessary to free any adhesions or sticking ofthe molded article to the mold sections.

After the molds have been filled and the vulcanizer has been closed bythe rise I58 of the disk I2I and the motor 18 stopped by passage of therise I58 beyond the cam follower I3I, an interval of time is requiredfor gelling, and accordingly the disks H9 and I20 are arranged to leavetheir cam followers I48 and I54 retracted and thereby leave the ventvalve I00 open and the steam valve 92 closed until such gelling intervalof five minutes as herelnbefore mentioned has elapsed after the closingof the vulcanizer.

At the end of this five minute interval the steam valve 82 is opened tosupply steam to the closed vulcanizer while the vent valve continues toremain open for three minutes-after the steam valve is opened and at theend-of this three minutes period the vent valve I is closed.

The steam valve 92 then remains open and the vent valve I90 remainsclosed until Just prior to the time that the vulcanizer opening rise I58of the disk I2I reaches the cam follower I3I, at which just prior timethe steam valve 92 is closed and the vent valve I30 opened and it willbe understood that these latter valve operations are caused to occursuiliciently in advance of the vulcanizer opening to insure relief ofpressure in the I vulcanizer before the vulcanizer is opened. motor 18to operate to close the vulcanizer, this 76 1 portion IBI' is engagedwith its cam follower m and I00, the disks IIS an I20, which continue torotate slowly while the vulcanizer is closed, have raised peripheralportions I60 and I 6| respectively, the latter of which reaches itscamfollower I54 and opens the steam valve 92 five .5

minutes after the rise I56 of thedisk I2I has passed its cam follower I3|, and three minutes thereafter, or eight minutes after the rise I56 ofthe disk I2I has passed its cam follower I3I'the raised peripheralportion I" -of the disk H9 10 reaches its cam follower I and closes thevent valve I00.

These raised peripheral portions Ill and IGI are continued around therespective disks H9 and I to substantially coincidental terminations is580' and I6 I, the latter preferably slightly ahead of' the former,which said terminations reach their cam followers Ill and I a fewminutes prior to the time that the rise III of the disk I2I reaches itscam follower I 2i, so that the steam 20 valve 92 is closed and the ventvalve Ill opened sufllciently before the vulcanizer opening by the riseI58 to insure atmospheric pressure in the vulcanizer before the latteris opened.

With this arrangement the raised peripheral a cycle of operations may beincreased or decreased as desired and the disks IIl, II 9, I 2| and I2Imay be plain circular disks with segments detachably or adjustablymounted thereon so that the times at which and the lengths of timeduring which the switches I35, I3, I52 and I2! or any 40 of them areopened or closed may be regulated. For example, as shown in connectionwith the disk I2II, the disk itself may be circular and have overlappingarcuate segments I" and I at opposite sides respectively thereof,secured to the disk I20 by bolts LN engaged through arcuate slots I 85of the segments so that the'segments may be adjusted circumferentially'to increase or decrease the length of the raised peripheral portion ItIor the place where such portion begins and ends.

Thus with the above vulcanizer and controls,

after the molds. have been filled, the op-I erator temporarily pressesthe push button I" thereby starting the timer motor I and rotat- 6! ingthe disks Iii-Iii which then act automatically to'first close thevulcanizer, then, five minutes after the vulcaniler isclosed, tointroduce steam into the vulcanizer while the vent remains open forthree minutes after which the vent is closed and the steam supplycontinued for twenty minutes whereupon the steam supply is discontinuedand the vent opened and after a safe interval for reduction of pressurein the vulcanizer the vulcani is opened, all being done automaticallyand hout any special skill of attention on the part of the operator. Thetotal time for processing, exclusive of removing the vulcanized articlesand cleaning and filling the molds and the slight delay for releasingany adhesions before the vulcanizeris fully opened amounts to onlyslightly in excess of twenty-eight minutes whereas vulcanizing' alonehas previously required approximately two hours with additional timerequired for removing the molded articles from the molds, cleaning andfilling the molds and loading them into and removing them from thevulcanizer so that the output from the molds with the above describedequipment is approximately six times or more greater than previously andwith assurance of better and more uniform processing and less loss andwastage than here- 25 tofore.

For convenience in opening or closing the vulcanizer independently ofthe timing controls and also for setting the motor Ii at the exact openor closed position in synchronization with the 9 timing controls, areversing control I" may be provided and it will be understood that byoperation of this reversing switch the shaft 26 may be operated'at anytime and to any extent and that the timing controls are not disturbedthereby.

while I have shown and described my invention in a preferred form, I amaware that various changes and modifications may be made therein withoutdeparting from the principles of my invention, the scope of which is tobe determined by the appended claim.

- I claim as my invention:

In-equipment of the class described, the combination of a mold, avulcanizer having separable parts which close together to substantiallyseal the mold in the vulcanizer, said mold comprising separable partswhich close together to form a covered mold cavity and which separate atsubstantially the place of separation of the vulcanizer parts, and meansoperable to supply a blast of cooled air between the separated separableparts of the vulcanizer against the separated parts of the mold therein,said last mentioned means including means for-directing the air up-EUGENE AUGUSTUS LUXEN'BERGER.

